1. Technical Field
The present invention relates to a droplet discharge method, an electro-optical device, and an electronic device.
2. Related Art
The droplet discharge head of an inkjet printer is able to discharge microscopic ink droplets in the form of dots, which affords extremely high precision in terms of the uniformity of the size and pitch of the ink droplets. This technology has been applied to the manufacture of many different products, such as electro-optical devices. For instance, it can be applied in the formation of a film for the light-emitting components of organic EL display devices or the color filter layers of liquid crystal devices.
More specifically, a droplet discharge head is filled with a special ink, a photosensitive resin liquid, or another such functional liquid, and droplets of this functional liquid are discharged onto prescribed portions provided on a substrate. The Japanese Laid-Open Patent Publication No. 2004-267927 is an example of related art. A number of different colors are usually formed in the light-emitting components or color filters used in modern electro-optical devices, and a plurality of types of functional liquid are discharged onto the substrate, each by a different device, one at a time.
When the apparatus discussed in the above mentioned reference is used, however, since a plurality of types of functional liquid are discharged onto the substrate by different devices one at a time, the overall discharge ends up taking a long time. In view of this, the idea was conceived to discharge all types of functional liquid with a single device in order to shorten the discharge time.
Also, the prescribed portions disposed on the substrate usually have a larger volume than the droplets of functional liquid, and cannot be fully filled with functional liquid in a single scan, so scanning is performed a number of times. A known method employed in these multiple scans is to have newly arriving droplets land in regions in between the droplets of functional liquid that have landed on the prescribed portions, and thereby cover up the bottom surface of the prescribed portions.
However, precise control is necessary to adjust the landing positions in order to have the newly arriving droplets land accurately in between the droplets of functional liquid as discussed above, and in actual practice this is exceedingly difficult. Also, when the above method is employed, the landing position is limited to just a small portion of the discharge region, and the landed droplets do not spread out sufficiently, so the droplets end up being disposed unevenly. When this happens, the film of functional liquid that is formed is not uniform, and this leads to inconsistent display in an electro-optical device, for example.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved droplet discharge method, an improved electro-optical device, and an improved electronic device. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.